TBH, "use a package manager, don't specify versions manually unless necessary, don't edit package files manually" is an instructions that most agents still need to be given explicitly. They love manually editing package.json / cargo.toml / pyproject.toml / what have you, and using whatever version is given in their training data. They still don't have an intuition for which files should be manually written and which files should be generated by a command.
>>miki12+(OP)
Agree, especially if they're not given access to the web, or if they're not strongly prompted to use the web to gather context. It's tough to judge models and harnesses by pure feel until you understand their proclivities.